This has not been an inspiring election campaign, but it has been a revealing one. It has not introduced many new arguments into the debate, but it has revived old ones - on immigration, on tax, on public services.

The divisions between the parties turn out to be as stark as ever. One benefit of this otherwise unedifying battle has been to kill off the lazy rhetoric of abstention. 'They' are not, as it has sometimes been fashionable to assert, 'all the same'. There is a choice. The Labour party offers progressive government in the face of xenophobic and reactionary Conservative opposition. It should be an easy decision to return Tony Blair for a historic third term. But for reasons that were unforeseeable in June 2001, it is not. It is no longer a question of party loyalty but of conscience.

That is a consequence of 11 September 2001, when Tony Blair's second-term agenda was thwarted by issues of security and diplomacy.

As the furore surrounding the Attorney General's legal advice on Iraq reveals, Tony Blair's decision to go to war remains the defining moment of his premiership. The damage it has done him will be recalled with fear whenever future Prime Ministers contemplate military action.

But the text of Lord Goldsmith's advice is not as damaging as the Prime Minister's enemies imagined. A case for going to war based on existing Security Council resolutions can be made, says the Attorney General, as can the case for ousting Saddam. The problem for Tony Blair does not rest in the legal advice, which backs his position. The problem is that he failed to trust either his Cabinet, Parliament or the British people with the fact that these are difficult arguments. The Prime Minister made a judgment on Iraq, a judgment this paper backs. He should have been more open with the information on which that judgement was made. If he had been, the understandable divisions over the war would not run as deep.

The Butler and Hutton reports revealed a system of government - conducted away from cabinet and with cavalier disregard for due process - that explains why Tony Blair has lost the backing of so many voters.

Under our constitution, a massive Commons majority gives the Prime Minister the ability to rule as if by decree. But that is no excuse to treat those outside a trusted 'inner circle' - including the legislative chamber and, as we reveal today, the armed forces - as if they can't be trusted with the facts. Labour promised to rewrite our constitution, to make Parliament's upper house more democratic and to dilute the power of the centre. That project stalled after devolution. The government's progressive intentions were trumped by its controlling impulses.

The same can be said of New Labour's record in the Home Office, where it has shown an authoritarian reflex. ID cards are an intrusion. They were sold to us, unconvincingly, as a panacea for ills ranging from global terrorism to benefit fraud, with no evidence that they will work. New Labour has pushed the prison population to a record 75,000. Anti-terror legislation has been drafted in haste and in thrall to security services. There has been an unseemly scramble to legitimise the objectionable practice of detention without trial in the name of national security. Principled objections were countered with scaremongering.

Blair's troubles over Iraq are, in fact, a reflection of a broader problem: he is too impatient with the rigmarole of democracy. He has encouraged a shift of sovereignty from Parliament to the Downing Street sofa that has undermined people's faith in government.

That is a shame, not least because it turns debate away from matters that affect the lives of British voters more than war. An emphasis on spin, secrecy and subterfuge does not do justice to this government. There are policies, implemented by New Labour, that should count for more in a general election, which, after all, is not a referendum on one issue. It is - or should be - a decision about the social, political and economic direction of the country.

Many Britons seem to take for granted the climate of steady economic growth, low inflation and low unemployment in which they live. It is easy to forget that such a combination was once thought to be economic alchemy. In the Eighties, full employment was dismissed as an old socialist fantasy; in many European countries, it is still a distant goal. In Britain, it is within reach and it has been delivered without stoking prices. Labour's poor reputation for economic mismanagement has been reversed.

The fruits of a buoyant economy have been spent on public services, reversing a decade of neglect and decline. This policy has created a new consensus on government's responsibility to invest. The old Conservative agenda of cuts, justified with assaults on the mythic inefficiency of the state has been killed off. Michael Howard is now taken to task over plans secretly to cut spending just as Labour once had to deny it would raise taxes. The NHS has been restored as the cornerstone of a welfare system with a universal health service free at the point of use. There are tens of thousands more nurses, doctors and teachers than there were in 1997.

Health spending in 2004-5 was £67.4 billion; it is due to rise to more than £100bn or around 9 per cent of GDP. Waiting lists have plummeted; the Conservative regime of 18-month waits for operations is banished. Spending per pupil on education has doubled since 1997. Spending on science and technology, a long-term investment in the economic future with few political rewards in the short term, will also rise to unprecedented levels.

Money has poured into schools and hospitals sometimes faster than they can spend it, hence the government's constant attempts to turn the political conversation to structural reform and its frustration when the subject keeps pinging back to Iraq.

A problem for New Labour is that some of its most creditable achievements do not directly affect the middle classes whom Tony Blair wooed so assiduously to get elected in 1997. Since then, according to the Institute for Fiscal Studies, the bottom 10 per cent of society are 10.8 per cent better off while the top tenth is 4.4 per cent worse off. New Labour, despite left-wing insistence to the contrary, has been quietly redistributing income as might be expected of a progressive government. Eight years of Labour rule have reversed the effects of the Tory decade that came before.

Flagship programmes to help deeply disadvantaged people have sailed under the media radar. Generous funding of further education, for example, has reduced adult illiteracy and innumeracy by 750,000 - likely to be 1.5 million by 2007. That significantly improves the lives of many people. The National Employer Training Programme will offer skills to up to eight million people who don't have them.

New Labour also delivered annual rises in child benefit, pensions and the creation of SureStart nurseries; the New Deal; the minimum wage; fuel credits for pensioners; restoration of employee rights; equalising the age of consent for gay men; implementation of the Human Rights Act; extension of the law against race discrimination; extension of disability rights; a commitment to eradicate child poverty. These are acts of a progressive government that has wrought gradual but significant changes on our society. The cruel edge of Thatcherism that fetishised individual success and scorned intervention for the sake of social justice has been challenged, if not reversed. Britain is a more just society than it was.

New Labour is also one of the most active progressive movements on the world stage, bringing environmentalism into the political mainstream and taking a lead in poverty alleviation and debt relief in the developing world.

These factors have not thus far been well deployed in the election battle. Neither, for that matter, have issues on which the government's record is weak: rail chaos; gridlocked roads; appalling suicide rates in prisons; the 35,000 teenagers who leave school each year with no qualifications; the lack of direction on Europe; frozen social mobility.

But in that respect the opposition, too, are found wanting. As bids for government, their manifestos are flimsy by comparison with Labour's. The Tories, in particular, have fought a shabby, racist campaign. A crushing defeat would do them the service of forcing a major strategic rethink.

They have failed again to challenge the Blair-Brown axis in the centre of British politics, wrapping themselves, instead, in nasty, illiberal reaction. They have ruled themselves out of contention by touting single-issue populism.

The Liberal Democrats, however, deserve credit for their principled defence of civil liberties and their honest approach to taxation. Their rhetoric on the environment and energy is welcome, if a little utopian, formulated safe in the knowledge that the ideas will not be tested by the exigencies of office. A substantial Lib Dem presence in the new parliament might force on them more rigour. That would be a welcome development for British democracy. Voters with sitting Liberal Democrat MPs should return them and voters choosing in marginal contests between a Tory and a Lib Dem should back Charles Kennedy. The Liberal Democrats are likely also to be the beneficiaries of a substantial protest over the Iraq war. They are the natural recipients of such votes.

But a general election is about more than protest. It presents a choice between competing propositions for government. It is not a referendum on a single issue, nor a choice between the incumbent administration and an ideal one.

A vote should not be cast in protest but to endorse a party, and the only party that offers progressive government committed explicitly to ending poverty and building social justice is Labour. The way to get a Labour government in most constituencies is to turn out and vote for one.